WASHINGTON -- Opposition leader Mir Hossein Mousavi urged supporters to attend another rally against the re-election of President Mahmoud Ahmadinejad, despite deadly attempts from the government to stop previous protests.
Via his profile on the social networking site Facebook, Mousavi revealed, "There will be another peaceful demonstration in Tehran to honor the martyrs on Thursday. Please update us with your 'Solidarity' events around the globe on Thursday."
Technology has played a large role in Mousavi's campaign as well as coverage of the post-election protests.
Eyewitnesses in Iran say riot police have attacked hundreds of election protestors with tear gas.
Grainy photos and videos from cell phones show police and militia dispersing a large crowd that gathered, Monday, in Tehran's public square.
Click play to watch John Jessup's report, followed by analysis from Michael Ledeen of the Foundation for Defense of Democracies. Ledeen has done extensive coverage on Iran and says the recent protests have "certainly frightened" the regime, but it's still unclear if they will make a great impact.
Iran's Revolutionary Guard have threatened to crush any further opposition protests. They say they will confront demonstrators if they take to the streets again.
The warning came after a weekend of massive protests and violent crackdowns that pushed the official death count to at least 17.
Mousavi vowed to keep up the fight -- disputing the results of Iran's June 12 elections. His claim that the vote was rigged in favor of Ahmadinejad prompted Iran's Guardian Council to investigate.
It now concedes there were irregularities in 50 cities, where the number of votes cast was far more than the number of registered voters, affecting the tally by as much as 3 million votes.
But the council insists no laws were broken and says the voting problems don't affect Ahmadinejad's win.
Defiant Mousavi supporters want to keep up the momentum but they are challenged with concerns for the safety of the protestors. At least 10 people died in clashes Saturday and nearly 460 were arrested that day alone.
But the demonstrations aren't limited to the streets of Tehran.
From California to the nation's capital, people marched in a show of solidarity for Mousavi supporters.
"My heart is with them. I wish I was there. I wish I could participate in the streets of Tehran," one protestor said.
"Freedom for the people. The right to vote. The right to have a fair election," another protestor said. "The things that we sometimes take for granted in this country, they're dying for . People my age, 24 years old, losing their lives," she added.
The unrest is fueling harsh attacks from some Republicans that President Obama should take a tougher stand.
"Now, I'm not for sending arms. I'm not for fomenting violence, nothing except to say that America's position in the world is one of moral leadership," Sen. John McCain R-AZ, said.
"He's been timid and passive more than I would like and I hope that he will continue to speak truth to power," Sen. Lindsey Graham R-SC, said on ABC's This Week.
"He's the President of the United States, not a member of the Senate or a columnist. He's got a very delicate path to walk here. I think he's been strong. You don't want to take ownership of this," Sen. Chris Dodd D-Conn., said on ABC's This Week.
Meanwhile, some analysts see a silver lining in the election fallout.
"And in a way, the regime could lose by winning," Karim Sadjadpour with Carnegie Endowment for International Peace said. "What I mean by that is if they continue to clamp down with overwhelming force, they're losing legitimacy by the day."
And that's good news for other Arab states in the Middle East.
They see a potential collapse of the regime as ultimately undermining Iran's history of meddling in the affairs of other government in the region by supporting radical groups like hamas and Hezbollah.